Hoisting apparatus



E.. W. HOLMES HOISTING APPARATUS FiledMarch 27,1944 s sheets-sheet 1IIIIIIILIIHH hun "PHL" llllll lllll j Emmi MMM@ Aug. H 1946. l E. w.HOLMES .2,405,573 I' HoIs'TING APPARATUS Filed March 27, 1 944 esneets-sneptz ug. 13, 1946. E. w. HOLMES HOI S TING APPARATUS FiledMaron 27., '1944 e sheets-sheet 5 Aug. 13,l 1946,

E. W. HOLMES HOISTING APPARATUS ug. i3, 1946. y E. w. HOLMES 2,405,573

.HOISTING APPARATUS l Filed-March 27, 1944 esheets-sheet 5 u J J J v J ul u z u J M Aug E3, i946. vE. w. HOLMES u y 2,405,578

HOISTING APPARATUS Filed March 27, 194A 6 Sheets-Sheet 6 j? v f5.5

gmac/Mofa A mw Pff/262m@ j B342@ la Wg Patented Aug. 131, 1946 HOISTIN GAPPARATUS Ernest W. Holmes, Chattanooga,

Tenn.; S.

Bartow Strang, administrator of said Ernest W. Holmes, deceased,assigner to Ernest Holmes Company, Chattanooga, Tenn., a corporation ofTennessee Application March 27, 1944, Serial No. 528,314

20 Claims. 1

The present invention reiates to improvements in hoisting apparatus, andmore especially to wreckers of the type employed for handling disabledautomotive and other vehicles and for other uses where hoisting,pulling, towing or similar operations are to be performed.

One of the primary objects of the invention is to provide novel andimproved operating and controlling mechanism for the cable winding drumswhereby the construction thereof is simplified and improved and theoperation thereof is facilitated.

Another object is to provide novel and improved driving mechanism forthe cable winding drums of apparatus of this character, and partieularly wreckers, of the double boom type in which each boom has a drumfor the boom cable and a drum for the hoisting or service cable, wherebyone or more or all of the drums may be operated at any time undercontrol of a single attendant and from a single power drive.

Another object of the present invention is to provide novel and improvedhoisting apparatus which, when mounted on a wrecking truck or othervehicle, is readily accessible' as to all of its 4parts for inspectionor servicing.

Another object is to provide a novel and improved frame in which themechanism of the hoisting apparatus is accommodated compactly and jwhichenables narrow hoisting drums of large diameter to be used, with theadvantage that fewer layers of cable requireto be wound thereon for acable of given length than heretofore, and thereby avoiding orminimizing wedging of the cable between convolutions of a lower layerthereof, as frequently takes place in winding a large number of layersof a tensioned cable upon a drum, the frame being so designed that suchnarrow large diameter drums may be readily removed edgewisetherefrom,should such become necessary for servicing or other purposes. Furtherobjects of the invention are to provide a novel and improvedconstruction of driving mechanism for the cable drums which facilitatesthe manufacture thereof, minimizes stresses I thereon under load,enables the parts thereof to be 'readily removed for servicing or otherpurposes, and which is otherwise well adapted to meet al1 of therequirements of heavy-duty apparatus of this type.

ATo these and other ends, the invention consists in certainimprovements, and combinations and arrangements of parts, all as will behereinafter more fully described, the features of novelty being pointedout more particularly in the claims at the end of this specification.

In the accompanying drawings,

vention, the same being shown mounted on a truck and adapted to beemployed as a wrecker;

Figure 2 is a top plan View ofa portion `of the apparatus shown inFigure 1;

Figures 3 and 3a are collectively a rear elevation of the apparatus onan enlarged scale, the booms being shown as swung from the oppositesides of the truck;

Figure 4 is a/detail View of one of the slings for the upper ends of thebooms:

Figure 5 is adetail view in vertical section of the driving gearing forthe boom and service cables of one of the booms;

Figure 6 is an elevation of the gearing as viewed from the right inFigure 5;

Figure 7 is a detail horizontal section taken on the line 1 1 in Figure6; f

Figure 8 is an elevation of the transferVV or` transmission mechanismthrough which the driving gearings for the booms and the service cablesare driven;

Figure 9 is a plan View of the transfer mechanism, with the coverthereof removed and parts shown in section;

Figure 10 is a section taken on the line lll-l0 f in Figure 8;

Figure 11 is an enlarged detailelevation of the lower portion of oneside of the frame, showing the drums for the service and boom cables;

Figure 12 is a rear elevation of the structure Figure 14 is a detailview showing the manner of attaching the sling to the sheave yoke at theupper end of the boom;

Figures 15 and 16 are detail sectional views showing the mountings ofthe swivels for the boom cable guide sheave and the boom respectively;and

Figure 17 is a detail horizontal section on the line l1|1 in Fig. 11.

Similar parts are designated by the same reference characters in theseveral figures.

The hoisting apparatus, according to the present invention, comprises aframe l, a pair of swinging boomsl 2, and cable winding drums andydriving mechanism therefor which form a complete unit. As shown inFigure 1,v this unit is a* adapted to be mounted on the chassis 3 of amotor truck so that the frame of the hoisting apparatus extendstransversely of the truck immediately behind the drivers cab 4, all ofthe parts of the hoisting mechanism being readily accessiblefromf therear and sides of the frame, as will hereinafter appear.

The frame I comprises a pair of parallel, spaced vertical columns 5 ateach side, each column being composed preferably of channel iron, a pairof horizontal base members 6, also preferably composed of channel iron,to the outer sides of which the lower ends of the columns 5 are riveted,welded or otherwise iixed and a similar pair of horizontal members Iconnecting the respective columns 5 and similarly iixed thereto. Angleirons 8 extend horizontally between and connect the tops and diagonalbraces S connect the ends `or the upper angle irons and plates IUriveted,

welded or Aotherwise xed to the lower portions of the columns 5. rlheframe is supported rigidly on the truck chassis.

The booms 2 are each pivoted on a horizontal pivot' I I carried by aswivel I2 having a vertical stem I3 tted rotatably in upper and lowerplates I4 bolted, welded or otherwise xed to the top ,and bottomrespectively of the base members t spanning the space between them, thebooms being thus mounted to swing upwardly and down- Wardly about thehorizontal pivot I I and to swing laterally about the vertical stem I3as an axis. The upper end of each boom is provided with a sheave l5lover which the hoisting or service cable I6 passes, this cable beingequipped at its 'end with a hook Il or other suitable means for engagingit with an automobile 'or other vehicle' or object to be hoisted orhauled, the sheave being journaled on a horizontal shaft I3 in a yoke i9swiveled in the upper end of the boom, a cable guide I?!a beingconnected to this yoke for causing it to swivel in the end of theboomwhen a load isr being pulled from either side thereof. The upper end ofeach boom is also equipped with means'vfor attaching a boom'cableYthereto for raising and lowering it. The boom cable is attached at oneend by a pin 2l to a sheave carrier 22, the latter Abeing pivoted by thehorizontal pin 23 to a swivel 24, the'latter having a hollow verticalstem 25 which is mounted rotatably in plates 26 which span the spacesbetweenand are bolted, riveted, welded or otherwise fixed to the tops ofthe angle irons 8 and the upper and loweredges of the channel irons '1.Each sheave carrierhas a sheave 21 journaled therein, around which theboom cable passes, the boom cable also passing around a pair of sheaves28 journaled on a pin 29 in a yoke 30.

The present invention provides novel means for attaching the boom cableyoke 30 to the upper end of the boom whereby the load on the boom'willbe distributed and sustained equally at opposite sides of the servicesheave I5, and such attaching means will avoid fouling with the upperend of the boom when the latter is raised. Such attaching meanscomprises a yoke 3I which is hooked by its intermediate portion in theyoke 30 and carries a pair of sheaves 32 which are journaled on a pin S3in the'yoke 3 l. The sheaves '32 are connected to the upper end of theboom by a sling composed of a suitable length of ilexible cable 34 theends of which are connected to form a loop, the intermediate portions ofthe loop being passed around the respective sheaves 32 and the ends of'the loop being passed around groved segmental bosses 35 on the outersides of CII the yoke I9, the pivot pin I8 for the service sheavepassing through these bosses and being removable without disturbing thesupport of the boom by the sling. Clamps 35 are preferably employed tobind together the ends of the loop adjacent to the sheave pin I8. Bythis arrangement, the load on the boom is divided between and sustainedby the ends of the sling at opposite sides of the service sheave, andthe portions of the load sustained by the ends of the sling areequalized by the sheaves 32, especially when the yoke i9 swivels in theupper end of the boom, as takes place while the service cable is pullinga load from a side of the boom, thus equalizing the tension on all ofthe boom supporting cables. The ends of the sling straddle the upper endof the boom as'the latter is raised, as shown in Figure 3a, thusavoiding interference with the raising of the boom to its extremeheight. An Outrigger leg 4!) is preferably provided for supporting theload on one or the other side of the frame while the boom at that sideof the frame is swung laterally from the truck to lift a load at a sidethereof. Each of these legs, as shown, comprises a pair of telescopicsections 4I and 42 adapted to be held adjusted to different lengths by apin 43 which may be inserted through holes in the section 4I and theappropriate pair of opposite holes 44 spaced longitudinally of thesection 42. The lower section Vof the leg is provided with a foot I2a tobear on the ground Ywhen the leg is extended laterally of the truck andthe section 42 lowered. The upper section of the leg is pivoted on ahorizontal pin 45 in a swivel .16 and the latter is provided with avertical stem or journal which is rotatable in plates 23 and 25aspanning the space between and secured to the frame members 1. Theuniversal pivoting of the legs 20 to the frame enables each leg to beextended at any angle laterally from the truck, as shown in Figure 3, tobring it beneath the respective boom and sustain a side pull or load,spreading of the lower end of the leg being prevented by a chain 41which may be attached to lthe lower end of the leg and one of the basemembers of the frame, and when the leg is not in use it may be foldedagainst a side of the truck, as shown in Figure 3a, and locked by aspring plunger 4B.

The service cable extends from the boom sheave IS over a sheave 50journalled in a swivel 5I' having a 4hollow vertical stem 52 rotatablymounted in a pair of the plates 2S of the frame, this cable passingthrough the stem 52 and winding on a hoisting or service drum 55. Theboom cable passes from one of the sheaves 28 over a. f

sheave 5l and downwardly through the respective swivel stem 25, thenaround a guide sheave 58 and winds on a drum 59.

Each service cable drum 55 is of relatively large diameter and ofrelatively short axial length, thus enabling a given length of cable tobe wound thereon with a fewer number or lay ers of the cable than ispossible with a drum of relatively small diameter, thus avoidingtendency of the service cable, while under load, to become wedgedbetween convolutions of an underlying layer, and the narrow dimension ofthe drum enables it to be accommodatedl between the upright columns 5 atthe respective sides of the frame. This drum 55 is mounted to rotate onor with a shaft 5B supported in bearings 60 in the relatively fixedplates I0 and from which it is removable axially, and the drum 55carries a driving gear SI which meshes with a pinion 62 loOSe- 1ymounted on a driving-shaft 63 and is coupled thereto by splines |63 anda clutch collar |63a slidable thereon, the shaft 63 being journaled inbearings 64 supported by the plates |0, and being removably retained insaid bearings by a plate l 638L secured to. the end of the shaft 63 by acap screw 63h. A band brake 65 is preferably provided for controllingthe slack in the service cable, this brake extending partly around thegear 6| and being drawn into frictional engagement with it by a tensionspring 66, one end of which is attached to the frame and the other endof which is connected to an arm 6`| fixed to and projecting radiallyfrom a shaft 68, the vlatter being mounted rotatably in the columns 5 ofthe frame and having a yoke 69 fixed thereon and connected to one end ofthe brake band 65, the other end of this band being connectedfat'f to asuitable part' of the frame. A loop extends radially from the shaft 68and is urged toward the portion of the service cable between the drumand the sheave 50. While theservice cable is under tension, as while aload is'thereon or this cable is being pulled to unwind it from thedrum, it will engage or swing the loop to rotate the shaft 68 againstthe action of the spring 66 and in a direction to release the brake band65 from the gear'l and thus avoid a drag upon the drum during lifting orlowering a load or while the service cable is being pulled manually fromthe drum,.but as soon as the service cable becomes slack, the loopdeflects the cable under the actionof the spring 66 and the latterrotates the shaft 68 in a direction to frictionally engage the brakeband 65 with the periphery of the gear 6|, thus avoiding over-running ofthe drum and consequent disarrangement of the cable thereon,

The drum 59 for winding the boom cable is removably mounted, by splines59a, on a shaft '|5 which is journaled in bearings 'I6 supported by therelatively xed frame plates I9, and removably retained therein by aplate |6a secured to the end of the shaft 15 by a cap screw 15a.

' vThe pinion shaft 63 for driving the service cable drum and the shaft'|5 on which the boom cable drum is splined extend rearwardly from theframe and have worm wheelsv Tl and "I8 respectively keyed or otherwiseremovably v'fixed thereon for driving them in relatively oppositedirections to wind lthe cables on the respective drums 55 and 59.According tothe present invention, the worm wheel meshes with a worm 19keyed or otherwise xed on a shaft 80, and the worm vwheel 18 meshes witha worm 8| keyed or otherwise fixed on a shaft 82 adjacent and parallelto the shaft 80. The worm shafts 80 and'82, which are driven inrelatively opposite directions, are mounted in bearings 83 which sustainthe radial and axial loads on these shafts, these bearings beingpreferably of theV annular ball bearing type and mounted removably in acasing 84 which contains or encloses the worm wheels" and 18, thisycasing having bearings 85 in which the shafts 63vand '|5 carrying theworm wheels are journaled. By so mounting the worm shafts in the casingand providing the casing with bearings for the worm wheel shafts, thecasing and worm shafts are supported on or suspended from vthe wormwheel shafts independently of the main frame I, and by removablymounting the drum 59 on the shaft '|5 and removably mount- -ing thepinion 62 on the shaft 63,v the casing 84 together with thev wormgearing therein can be removed as aunit after the plates 63a and 16ahave beenremoved and the torque screws 96 and 6. 91 loosened,4 forinspection or repair of these units or adjacent parts in the frame. Asthe cable winding drum is mounted rotatably on the shaft 56 and thelatter is removable axially from its bearingsdn the plates I6, this drummay be readily removed edgewise from the adjacent side of the frameafter removal of its shaft. The torque reaction between the casing 84and the worm wheel or '|8 while being driven by its respective worm issustained by thrust screws 96 and 9`| which are adjustable in brackets498 and 99 xed to the rear side of the main frame, these screws beingadjusted to bear against the resective ends of the casing 8.4, although,while -both worm wheels are being driven simultaneously, the torquereaction upon the casing 84 in one direction will neutralize the torquereaction thereon in the other direction, due to the opposite directionsof rotation of the worm wheels 11 and 18. l Y The casing 84 ispreferably composed of a pair of duplicate halves 84a and 84h united byanges 86 which may be bolted together, as shown, this design of thecasing enabling a single pattern to be used for both and otherwisefacilitating the manufacture thereof. The bearings83 for the worm shaftsare removable axially, thus enabling the worm shafts and thewormsthereon,l which are of smaller diameter than the bearings, to be removedaxially from the casing for servicing or replacement.` The bearings 83are retained in the casing by end plates 8l which are bolted orotherwise removably secured thereon, these end plates sustaining the endthrust of the Worms.' In order to prevent unintentional lowering of theboom or unwinding of the service cable, due to tendency of the wormgearing to back off under a load, because of the low resistance of theanti-friction bearings for the worms, each of the worm shafts 86 and 82which operate the service and boom cable drums 55 and 59 respectively ispreferably provided with a friction brake which will prevent unwindingof the service or boom cable from its respective drum, but will notinterfere with the normal lifting and lowering operations of thesecables. Each friction brake comprises, in the present instance, afriction cone 90 which is keyed on the' respective worm shaft and abutsagainst a shoulder 9| thereon, and an outer cone 92 which is movableaxially on the worm shaft and is urged against the cone 96 by acompressed coil spring 93 which encircles the worm shaft. The peripheryof the outer cone92 is provided with a pair of axially extending ribs 94between which a pin95 threaded into the casing projects, this pin andthe ribs .permitting axial movement of the outer cone 92 but preventingrotation thereof, whereby the reaction off the frictional braking torqueapplied to the Worm shaft by the inner cone 98 will'be sustained. Thepresent invention provides novel and improved transfer orv transmissionmechanism whereby power may be applied to either service or boom drum orto any number or all of these drums, as may be desired. Such mechanism,as shown in the present instance, comprises pairs of axially alinedshafts |09 and |0| journaled in bearings |92 and |83 respectively, whichare bolted or otherwise rigidly fixed in the opposite side walls of acasing |04 having a removable cover |649. `The outer vends of the shafts|60 are connected by couplings |66 to the worm shafts 80 which drive thedrums 55 for the service cables for the respective booms, and the outerends 'of 7 the shafts IDI are connected by couplings |01 to the wormshafts 82 which drive the drums 59 for the boom cables for therespectivebooms. The inner ends of the shafts have jaw clutch members.|08 and |09 splined thereon to shift axially although connected torotate therewith, and the inner ends of the shafts |0| have similar jawclutch members |I0 and ||I splined thereon to shift axially althoughconnected to rotate therewith. A shaft ||2 is interposed between theinner ends of the shafts |0| in axial alinement therewith, the ends ofthis shaft being reduced and journaled rotatably in the inner ends oftheshafts |0|, and the shaft IIZ has a jaw clutch member I i3 and a gearI I4 keyed or otherwise fixed thereon, the gear I|4 having jaw clutchteeth ||5 fixed thereon, the clutch member I3 and clutch teeth |I5 beingcompanions tothe clutch members ||0 and III respectively, and beingengageable therebtT to connect the shaft ||2 to the respective shafts|0I. A shaft |16 similar to the shaft II2 is interposed between theinner ends of the shafts |00 in axial alinement therewith, and hasreduced ends journaled rotatably in the inner ends of the shafts |00,and the shaft ||6 has a jaw clutch member I I1 and a gear I I8 keyed orotherwise fixed thereon, the gear ||8 having clutch teeth ||9 thereon,the clutch member ||1 and the clutch teeth on the gear ||0 beingcompanions to the clutch b members |00 and |09 respectively, and beingengageable thereby to connect the shaft I|6 to the respective shafts|90. Power is applied to the shaft ||2 by a shaft |20 which is journaledin a bearing |2| bolted or otherwise fixed in an end wall of the casing|04, the shafts ||2 and |20 being connected by bevel gears |22 and |23keyed or otherwise xed to the respective shafts, and the gears ||4 and||8 fixed on the shafts H2 and 6 mesh with one another whereby the shaftI I6 is driven from the shaft I I2 but in the opposite direction ofrotation. The shaft preferably receives power for rotating it in one orthe other direction for lifting or lowering operations from any suitableor well known form of power take-olf from the usual truck engine, as,for example, from asprocket wheel |24 driven in one or the otherdirection by any usual or conventional form of reversible power take-offfrom the transmission |25 of the truck, a chain f |26 driven fromv saidsprocket wheel, and a sprocket Wheel |21 fixed to the shaft |20. pThefour jaw clutches thus provided in the transfer` mechanism enable anyone or more or all of the shafts |00 and |0| to be driven by power fromthe single power shaft |20, and meansris provided for controlling theseclutches from a remote point, preferably the cab of the truck. Suchcontrolling means, as shown in the present instance, comprises a set ofBowden wires I3I, |32, |33 and |34, the outer tubes or casings of whichareheld, kas bya clamp |35, on thedtop of the casing |04 .and the innerwires of whichextend into the cab where they arevconnected to levers,knobs or other appropriate control members within convenient reach of anattendant in the cab. The other ends of the wires are operativelyconnected to levers |30, 31, |38 and |39 above the cover |04a of thecasing |04, these levers being xed to the upper rends of shafts |49,'|4I, |42 and |43, respectively, journaled in suitable bearings in thecasing |04. The shafts |40, I4I, |42 and |43 have forks |44,'|45, |46and |41, respectively, xed thereon, these forks cooperating with groovedcollars on the sliding clutch members |08, |09, ||0 and ||I, re-`spectively, whereby rotation of each shaft in one or the other directionby pulling or pushing its respective Bowden wire .will slide therespective sliding clutch member into or out of engagement with itscompanion clutch member. Means is preferably provided for yieldinglyretaining each sliding clutch memberv in engaged or disengaged position,such means, in the present instance, comprising a bowed spring |48pivotally connected at one end to a hook |49 fixedin the` adjacent endof the casing |04 and pivotally connected at its other end to a pin |50fixed in the respective clutch shifting fork. The spring |48 normallytends to contract or close, thereby biasing ,the pin |50 on therespective clutch shifting fork in a direction toward the hook |49, andthe hook |49 and pin |50 are so located on opposite sides of therespective clutch shifting Shaft that the pin |50 will move to one orthe other side of a dead center position as the respective shifter forkis rotated to engage or disengage the respective sliding clutch member,each spring thus serving to yieldingly retain the respective slidingclutch member in engaged or disengaged position. p

The transfer mechanism, as shown, is so designed that its mechanism maybe readily removed from the casing |04 for servicing or other purposes.The bearings |02 and |03 are bolted or otherwise removably fitted in theopposite sides of the casing, and by removing these bearings and theirshafts, the latter are withdrawn from the ends of the shafts ||2 andIIB, thereby releasing these latter shafts for removal freely throughthe open top of the casing |04 While the cover |04a thereof is removed.As the sliding clutch members are splined removably on the inner ends ofthe shafts |00 and |0|, they alsoare readily removableefrom the open topof the casing. The axial thrust on the shaft ||2 from the bevel gear |22is sustained by an antifriction thrust bearing which abuts at one sideagainst the inner end of the respective bearing |03 and at its other endagainst a shoulder |50 onthe respective shaft |0I, and this shaftcontains an anti-friction thrust bearing- |51 against which the adjacentend of the shaft ||2 abuts whereby the amal thrust from the.. beve1 gear|22 is ktransferred from the shaft ||2 to the respective shaft |0| andfrom the latter through the bearing |55 to the adjacent bearing |03. Theaxial thrust of the other bevel gear |23 is sustained by the inner endof the bearing I2I through an anti-friction thrust bearing |58 which isinterposed between its inner end and the gear |23. Oil Seals |59 areprovided for the shafts |00 and |0| whereby an oil bath may bemaintained in the casing |04 and leakage therefrom prevented.

In some instances, it may be desirable to tie together the upper or freeends of the booms andA thus providexa rigid structure and the hoisting,towing, pulling orY hauling may be done conjointly by both booms, one'of the booms being provided for such purposes with an apertured lear|60 projecting from a side thereof and the other boom with a socket IISIto receive said ear when the boomsY are brought together, a springactuated locking pink |92 being carried by the socket and engageable inthe aperture of the ear, substantially like the boom locking arrangementdisclosed in my prior Patent Reissue No. 14,720, granted September 2,1919.

The construction .and operation of the various elements of the apparatushaving beendescribed in detail, the generaloperation of the 'completeapparatus is as follows: Normally, or whilelthe apparatus is in transit,both booms are preferably swung to the vrear of the truck and tiedtogether by the locking of the servicev or boom cables from their' drumsunder the inuence of the load being prevented by the friction brakes 9d,92 on the shafts of the worms which drive the service and boom cabledrums 55 and 59.

The hoisting, towing, pulling, hauling or other operations may beperformed either whilev the booms are tied together and sustain the load.conjointly, or such operations may be performed by either or both ofthe booms operating separately, as while one boom is being employed tohoist, pull, haul or otherwise operate upon a load sustained by oneofthe booms while swung to one side of the truck while the other boom isswung to the other side of the truck and itsserv- 'ice cable is attachedto an anchor so that this service cable acts as a guy for the other boomwhichsustains the load.

Assuming the booms have been arranged'ap- -propriately for the operationto be performed, the

power take-off from the transmission of the truck will ybe put intooperation for lifting, the power shaft |28 being thereby drivencontinuously in the appropriate direction by power taken vfrom the usualengine of the truck. In order to lift one or the -other b-oom, theBowden 4wire |33 or |34 is pulled, thereby shifting the respectivesliding clutch member H or to couple the shaft l2 to the respectiveshaft liil, in consequenceof which the respective worm 8| will drive itscooperating worm wheel 'I8 in a direction to rotate the boom operatingdrum 59 in a direction towind the respective boom lifting cable 20thereon, thus lifting the respective boom, and when ,such boom reachesthe desired height, the clutch member which was engaged will -bedisengaged from its companion clutch member by pushing the respectiveBowden wire |33 or |34, thus stopping the boom lifting operation, andthe boom will be held in its adjusted position by the irreversibleaction of the respective worm 8| and cooperating worm wheel 18; or whenboth booms are to be raised simultaneously, both clutch members l0 andare engaged at the same time.

y After the boom employed for hoisting, pulling, hauling or similaroperation has been thus adjusted to the` desired height or angle, theapprpriate Bowden wire |3| or |32 is pulled, thereby shifting therespective, sliding clutch member |8 or |69 into engaged position andtherebyl coupling the shaft 6 to the respective shaft |00, causingoperation of such shaft Vto drive the respective worm 19 and therebydrive its cooperating worm wheel l1 in a direction to rotate the drum 55to wind the service cable lli'thereon. Since the load to be lifted orpulled is attached .to the hook on the service cable, the load will pin-|B2,ounintentional unwinding f either or both booms and operate 'either'or both be lifted or lpulled until the respective clutch` `member |08 or|99 is disengaged from its companion clutch member by pushing therespective Bowden wire |3| or |32, whereupon the lifting or pulling vofthe load will be stopped, and the load will be supported by theirreversible action of the respective worm -'|9 and worm wheel 11.

When both service cables are employed at the same time for hoisting,pulling or similar operations, both clutch members |08 and |09 areengaged at the same time by simultaneously pulling both Bowden wires l3|and |32.

In some instances, it may be desired tolift event, it is merelynecessary to pullgthe appropriate ones or all of the Bowden wires,qall;oi the power for these operations being .provided bythesingle powershaft-IML e In order to lower one or the other boomorto lowerthe'service cable tov which the-load is attached, the power take-offfrom the triuck transmission is reversed or set tov drive vtheshaft'lZllyin the opposite direction to thatfor lifting, and

the sliding clutch member corresponding to the boom or service cable tobe lowered' is engaged with its companion clutch member by pulling 'therespective Bowden wire, thereby causing power to be taken from the shaftv|20 to rotate thefrespective worm and cooperatin'g'worm v.wheel torotate the corresponding boom' drum or vservice drum in a direction tounwind the respective boom or service cable, and, obviously, one or moreor all of the boom and servicedrums may vbeadriven simultaneously, ifdesired the 'power therefor being supplied from the single. power`'shaft-'Hitt The torque reaction between the worm wheel T! or 'i8 andthe casing 84 will be sustained -by the stops or adjustable screws 93and Qlgwhich-abut against the ends of the respective casing 8d, although`y`when bothv worm wheels-'Ill and i8 `are driven simultaneously toraise the, 4resrnective boom and lift or pulla load on the.servicefcab-le for that boom, the torque reaction on thejcasing B4 fromone worm will be neutralized more or less by the torque reaction fromthe othernworm wheel, it being noted that the worm wheels and 'I8 aredriven in opposite directions to windthe cables on the drums 55 and 59,res1:xectively.L

Also, as the axial thrusts'of the worms '19 and 8| are in oppositeldirections during theirgoperation to raise the boom and lift theservice. cable, the reactions of such aXialthrusts are distrib.- utedbetween the opposite vsides of ,the casing 83, thus enabling this casingto be constructed of r.el atively light weight,- and thetorque/sustaining screws for thisy casing 'may also be lofrelativelylight weight. As each casing-84 is mounted on the respective worm wheelshafts B3 and 15 and may each be removed asa unit therewith ashereinbefore described, these units and also the rear side of the framein the region in;which.the drums 55 and 59v are located are readily madeaccessible. f

The large diameter service drums 55 employed not only enable asuiiicient length vof service cable to be wound thereon in a minimumnumberof layers, thus avoiding wedging of the cable between theconvolutions of the layerslwound on vthe-drum under tension of the load,butI also enable` drums length to be employed. Such narrow'drums'may beaccommodated in a narrow frame 'which may be conveniently mountedtransversely on a truck immediately behind the'cab, thus renderingr therear side of the frame accessible for servicing of the mechanism thereinandl leaving the rest' of the truck body available for loading or lotherpurposes, and the narrow service drums, as well as the boom operatingdrums 59, may be-'readily removed edge wise from the respective' en dsofthe frame,l after removal of their shafts, vfor servicing or otherpurposes.

The employment vof wormsand worm wheels for driving the service and boomwinding drums greatly simplifies the'apparatus since these worms andworm wheels are irreversible, thatv is, the worms will hold thewormwheels against retro,- graderotation under the loads imposed upon-theservice and boom winding drums, 'and will automatically hold the loadand the boom at anyheight to which the same are lifted, therebyobviating the necessity of employing complicated ratchets for lockingthe drums, and releasing and controlling means for unwinding the cablesfrom the drums, as heretofore. Also, the present invention provides anovel transfer mechanism whereby the power for driving the drums to bothwind and unwind the service and boom cables may be derived Vfrom asingle power shaft which may .be driven conveniently by the usual engineof the truck on which the apparatus is mounted.

The present invention provides a heavy duty apparatus of great :powerand strength for performing efcietly and rapidly a variety ofoperations, such as lifting, pulling, hauling or towing disabledautomobiles -or other vehicles or apparatus, in vwhich all of the powerrequired is supplied from a single source and may be controlledconveniently, as from the cab of a truck, and the various parts of theapparatus are readily acces- Y siblefor inspection, :removal or otherservicing.

I claim as -my invention:

.1. 4Hoisting apparatus comprising a frame, a boommounted thereon,service and vboom operating .cables cooperative with the boom, drums forwinding the respective cables, shafts mounted on the frame and connectedto the respectivedrums for driving them, a worm wheel fixed to each ofsaid shafts, a casing supported directly by said shafts independently ofthe frame, worms mounted in said casing and vcooperative with therespective worm wheels for operating them, and means on the frame andcooperative with said casing for sustaining the torque reaction of saidworm wheels thereon.

2. Hoisting apparatus according to claim 1, wherein said torque reactionsustaining means comprises abutment members on the frame engagingopposite portions of said casing.

3. Hoisting apparatus according to claim 1, wherein said torque reactionsustaining means comprises a pair o'f alined screws mounted on the frameand adjustable into abutting relation with opposite portions of saidcasing. Y

4. Hoisting apparatus according to claim 1, wherein said worm wheelsrotate in relatively opposite directions to operate the respective drumsto 4wind the cables thereon.

5. Hoisting apparatus according to claim l, wherein said worms aremounted in parallel relation in said casing and rotate said worm wheelsin relatively opposite Adirections to wind the respectivev cablesthereon, and means for sustaining the thrust of said worms against therespective ends of said casing.

6. Hoisting apparatus comprising a pair of booms, service and boomoperating cables for each boom, drums for winding the respective cables,gearings individual to said drums for the respective booms for operatingthem, a power shaft, and transfer mechanism interposed between saidgearings and driven by said power shaft and comprising clutches forindividually connecting the power shaft to the respective gearings forselectively operating the service and boom cable drums for both boomsfrom said power shaft.

7. Hoisting apparatus according to claim 6, wherein said transfermechanism comprises a pair of shafts, gearing connecting them to rotatein relativelyreverse directions, one of said shafts being connected tosaid power shaft to be driven thereby, clutch members on said pair ofshafts,

12 companion clutchrmembers connected respectively to said gearings, andmeans individual to said clutch members and companion clutch members forengaging and disengaging them.

8. Hoisting apparatus according to claim 6, wherein said transfermechanism includes means for each of said clutches for yieldinglyholding the same in engaged and disengaged conditions.

9. Hoisting apparatus comprising a boom, service and boom operatingcables cooperative therewith, drums for winding and unwinding the'-respective cab1es,'worm wheels disposed in different but adjacentplanes land connected to the respective drums for operating them, acasing composed of similar halves enclosing the respective worm wheels,and a pair of worms journaled 'in the ends of the respective casingvhalves in acljacent parallel relatlon and engaging the respective wormwheels.

10. YHoisting apparatus comprising a frame, a pair of booms .mountedthereon, service and boom operating cables cooperative with therespective booms, drums mounted in the frame for winding and unwindingthe cables, gearing including worm wheels connected to the drums foreach boom and a pair of worms meshing respectively With the worm Wheelsfor the respective boom, transfer mechanism comprising a casing, a powershaft journaled therein, a pair of driving shafts connected to the powershaft and provided with clutch members, pairs of driven shafts journaledin the opposite sides of the casing in alinement with and supporting therespective driving shafts and having sliding clutch members on theirinner ends to cooperate with the .respective clutch members on saiddriven shafts,

Yand having `parallel upright columns providing openings vat 'theopposite ends of the frame and at the respective sides of the truck,booms swiveled on the frame adjacent to its opposite ends, service andboom operating cables cooperative with each boom and extending into therespective ends of the frame, 'drums for winding said cables movableedgewise into and out of operative positions between the columns throughsaid openings at the respective ends vof the frame, and shafts mountedin the frame for removably supporting the drums therein for rotation ina common plane. I

12. Wrecking apparatus for mounting on a truck transversely and behindthe cab thereof, comprising a 'relatively narrow frame having drums'mounted in a common plane in each end thereof at the respective side ofthe truck for winding a servi-ce cable and a boom operating cable, aboom swiveled on a vertical axis adjacent to each end of the frame andcooperative with said service and boom operating cables, sets ofgearings at a side of the frame and'adjacent to the respective endsthereof for operating the drums for the service cable and boom operatingcable for the respective booms, and transfer mechanism mounted at saidside of the frame midway between its ends and between said sets ofgea-rings and connected to Said sets of gearings for operating them.

13. In hoisting apparatus, 'a boom, a sheave for a service cableswiveled in the end of the boom for rotation about the longitudinal axisof the boom as a center, a boom operating cable, a supporting sheavehaving a shaft connected to the boom operating cable, and a sling havingits ends connected to the outer` end of the boom at opposite sides ofsaid sheave, and having a portion thereof between its ends extendingaround said supporting sheave connected to the boom operating cable.

14. In hoisting apparatus, a boom having a sheave mounting swiveled inthe end thereof for rotation about the longitudinal axis of the boom asacenter, a service cable sheave supported by said mounting for rotationon a substantially horizontal axis, a boom supporting cable, a pair ofsupporting sheaves having a shaft connected to said cable, and a slinghaving its ends looped and engaging the sheave mounting at oppositesides of the service cable sheave, and having its intermediate portionsextended around said pair of supporting sheaves.

15. Hoisting apparatus comprising a boom, service and boom operatingcables cooperative therewith, drums for winding the respective cables,worm and worm wheels connected to the respective drums for rotating themto wind and unwind the respective cables, power means for operating theworms, and a friction brake cooperative with each worm for holding itagainst rotation independently of the power means, said friction brakecomprising inner and outer conical members, one of which is fixed toturn with the respective Worm, and means including a pin cooperativewith the other conical member to permit axial movement but preventrotation thereof.

16. Hoisting apparatus comprising a narrow elongated frame, a pair ofbooms mounted respectively on the ends thereof, service and boomloperating cables for each boom, drums mounted in the respective ends ofthe frame for Winding the respective cables, gearings adjacent to therespective ends of the frame and individual to said drums for operatingthem, a power shaft mounted between the ends of the frame, and transfermechanism mounted adjacent to and driven by said power shaft andcomprising clutches for individually connecting the power shaft to therespective gearings, and means connected to said clutches forcontrolling them from a remote point.

17. Hoisting apparatus comprising a frame, a boom pivotally mountedthereon, a service cable carried by the boom, a boom supporting cableconnected to the boom, a pair of drums mounted in said frame adjacent tothe pivotal mounting of the boom for winding the respective cables, acasing adjacent to the pivotal mounting of the boom, a pair of wormwheels mounted in the casing and connected respectively to said drums, apair of worms mounted in the casing and cooperating respectively withthe worm wheels, a power shaft, means operable by the power shaft 14 forrotating said worms in relatively opposite directions to operate thedrums to wind the respective cables, and clutches between the powershaft and said Worms for selectively connecting the latter to the powershaft.

18. Hoisting apparatus comprising a frame, a boom pivotally mountedthereon, a service cable carried by the boom, a boom supporting cableconnected to the boom, a pair of drums mounted in the frame adjacent tothe pivotal mounting of the boom for winding the respective cables, acasing adjacent to the pivotal mounting of the boom, a pair of wormwheels mounted in the casing in overlapping relation and in adjacentlylocated planes, a gear connected to one of the worm wheels andcooperative'with one of the drums, a shaft connected to the other ofsaid worm wheels and connected directly to the other drum, said gear andshaft rotating the drums in the same cable winding direction by rotationof the worm wheels in relatively opposite directions, a pair of wormsmounted in said casing and meshing with the respective worm wheels, apower shaft, and worm driving shafts having means for connecting them tothe power shaft to rotate the worm wheels in relatively oppositedirections to wind the cables on the respective drums.

19. Hoisting apparatus comprising a frame, a pair of booms pivotallymounted at opposite ends thereof, service cables carried respectively bythe booms, boom lifting cables for the respective booms, service andboom cable operating drums mounted in the respective ends of the frameadjacent to the pivotal mountings of the respective booms thereon, apair of gearings at a side and adjacent to the respective ends of theframe and connected to the respective adjacent drums for operating thedrums, a power shaft mounted intermediately between the ends of theframe, pairs of shafts extending longitudinally at said side of theframe, means for connecting the shafts of each pair respectively to thegearings for operating the service and boom cable drums adjacent to therespective ends of the frame, and means including clutches forselectively connecting the shafts of said pairs to the power shaft.

20. Hoisting apparatus comprising a boom, service and boom operatingcables cooperative therewith, drums for winding the respective cables,worm wheels disposed in different but adjacent planes and connected tothe respective drums for rotating them to wind and unwind the respectivecables, worms mounted on adjacent parallel axes and cooperating with therespective worm wheels, power means for operating the worms, clutchesfor connecting and disconnecting the worms and power means, and frictionbrakes constantly acting on the respective Worms to resist rotationthereof and thereby hold them against rotation under the influence ofthe respective worm wheels while the worms are disconnected from thepower means.

ERNEST W. HOLMES.

